Date & Unix Timestamp Converter Online
This free date converter translates dates and times between the formats developers meet every day: ISO 8601 strings, Unix timestamps in seconds or milliseconds, RFC 2822 dates, and fully custom patterns. Convert an epoch value from a database into a readable date, or turn a human-readable date into the exact timestamp an API expects.
A "Now" button fills in the current moment in the selected input format, and custom patterns use the widely adopted date-fns tokens (yyyy, MM, dd, HH, mm, ss). All conversion happens in your browser.
How to use Date Conversion
- Select the Input Format that matches your source value (ISO 8601, Unix seconds, Unix milliseconds, RFC 2822, or Custom).
- Type or paste the date into the Input value field — or press Now to use the current time. For Custom formats, set the pattern with date-fns tokens such as yyyy-MM-dd HH:mm:ss.
- The result appears instantly in every format at once — ISO 8601, Unix seconds and milliseconds, RFC/UTC string, local time, and a relative time — each with a copy button.
- A live clock at the top shows the current Unix timestamp (seconds and milliseconds) and ISO time, ticking every second.
The formats explained
- ISO 8601 — the international standard, e.g. 2026-08-07T14:30:00.000Z. Sorts naturally as text and is the default in JSON APIs and databases.
- Unix timestamp (seconds) — seconds elapsed since 1 January 1970 UTC (the epoch), e.g. 1786458600. Common in APIs, JWTs (the exp claim), and Unix systems.
- Unix timestamp (milliseconds) — the same count in milliseconds, e.g. 1786458600000. What JavaScript's Date.now() returns.
- RFC 2822 — the email date format, e.g. Thu, 07 Aug 2026 14:30:00 GMT, still used in HTTP headers and RSS feeds.
- Custom — any pattern built from date-fns tokens, e.g. dd/MM/yyyy for European dates or MMM d, yyyy for readable labels.
Related terminology
- Unix epoch
- Midnight UTC on 1 January 1970 — the zero point from which Unix timestamps count seconds or milliseconds.
- ISO 8601
- The international date-time standard written year-first (2026-08-07T14:30:00Z), unambiguous across locales and sortable as plain text.
- UTC
- Coordinated Universal Time, the global reference timezone. The trailing Z in ISO strings means the time is expressed in UTC.
- Format tokens
- Pattern letters that stand for date parts in custom formats: yyyy = year, MM = month, dd = day, HH = 24-hour, mm = minutes, ss = seconds.
Frequently asked questions
- How do I convert a Unix timestamp to a readable date?
- Set the Input Format to Unix Timestamp (seconds or milliseconds depending on your value), paste the number, choose ISO 8601 or a Custom output format, and press Process.
- Is my timestamp in seconds or milliseconds?
- Current dates are 10 digits in seconds (about 1.7–1.8 billion) and 13 digits in milliseconds. If the converted date lands in 1970, you likely picked seconds for a milliseconds value.
- What do yyyy, MM, dd, HH, mm, and ss mean in custom formats?
- They are date-fns pattern tokens: 4-digit year, 2-digit month, 2-digit day, 24-hour hours, minutes, and seconds. Combine them freely, e.g. dd.MM.yyyy HH:mm.
- How do I get the current timestamp?
- Choose the input format you want (for example Unix seconds) and press the Now button — the field is filled with the current moment, ready to convert or copy.